Apologies for cross-posting.

For the intrepid, there is a new version of my dssi~ external available at: http://www.puredata.org/Members/jb/dssi%7E/view

Added: support for multiple plugin instances from a single dssi~ object.

I say intrepid, because it is not at all finished, it is undocumented and is Linux only at the moment, although I do have an OS X version kicking about somewhere if anyone is interested.